A New Year’s Resolution Kept – Eventually!

We all have the best of intentions at the start of the New Year, but we don’t always have the follow through. After 15 years as an independent consultant, I decided that it was time to give my web site a ‘Spring Clean’. Fortunately, I have a friend who is an expert in web site development https://www.linkedin.com/in/charles-lambert-aa436013/.

I am pleased to say that the new web site is now launched, and it describes my activity better than before. The web site is accompanied by a blog, which will look at topical questions and issues. If you have any feedback or ideas on reading the blog, please let me know. My plan is to write a couple of blogs each month to share what’s on my mind, point out issues or problems, or explore interesting aspects of the membrane water industry. Any feedback will encourage me to keep going!

Little did I know when I started this process that the World would be plunged into turmoil by COVID-19, though the first signs of the crisis were already emerging in January. One of the consequences has been that on-line communication has taken over from physical contact. For independent consultants this is fairly normal, but we still expect to attend conferences and client meetings. It constantly amazes me to what extent incidental conversations at conferences can turn into important new lines of enquiry, or areas of interest, or how the sharing of information can often solve problems.

The Problem for Desalination as an Occasional Back up

A case in point was a conference in Brighton in February which addressed water resource issues as a response to climate change. Southern Water described their unexpected perspective. Compared to the usual locations for desalination plants, most people think of the south east corner of the UK as cold and damp. However, as those of us who live here can testify, this is not the whole story. It is in fact cold, damp and crowded! And there are occasional long periods when it is not that damp.

A shortfall in water resources is looming, projected to be 190 mld for the Southern Water area by 2027. Surface or groundwater abstraction cannot meet the demand, and in fact, the world famous chalk streams of the area would benefit from higher flows.

Wastewater reuse and desalination are actively being considered as options and probably both will be needed. In round terms, the energy cost of reuse is about three times treating freshwater sources, and desalination is a further factor of three higher than reuse. Clearly, if these plants were part of the supply mix, they would only be operated when absolutely needed, especially desalination plants, since otherwise the energy footprint of water supply would increase sharply.

But how suitable are desalination plants for intermittent use? Thames Water gave a presentation on the experience of operating the Beckton plant which reminded me of the dire warnings of the three witches in Macbeth! It could leave the faint hearted feeling nervous. Their experience had not been a happy one. Long shutdowns had compounded the problems of a complex design. In contrast, most desalination plants, i.e. those in the Middle East, operate continuously at full design flow. The challenge for a future in which desalination is routinely used for occasional drought relief is to provide plants which are capable of being moth-balled and easily brought back into service. A simple process flowsheet would be the first pre-requisite to ensure flexibility for intermittent use.

Many of us now have an extended opportunity for reflection and I would be interested to hear what others are thinking about on this and other conundrums.